Unavailable

This appears to be based on a HOAX that was reported by the Associated Press in Lebanon on the 9th May 1999. That HOAX claimed that the Chernobyl (CIH.1003) computer virus would infect and damage mobile phones in that country on Saturday. You can read the AP article here http://cnn.com/WORLD/meast/9905/09/lebanon.cell.hoax.ap/. (This original article doesn't seem to be there anymore.)

Dear all mobile phone's owners,
ATTENTION!!! NOW THERE IS A VIRUS ON MOBILE PHONE SYSTEM.

All mobile phone in DIGITAL system can be infected by this virus. If you receive a phone call and your phone display "UNAVAILABLE" on the screen (for most of digital mobile phones with a function to display in-coming call telephone number), DON'T ANSWER THE CALL.
END THE CALL IMMEDIATELY!!!
BECAUSE IF YOU ANSWER THE CALL, YOUR PHONE WILL BE
INFECTED BY THIS VIRUS.
This virus will erase all IMIE and IMSI information from both your phone and your SIM card which will make your phone unable to connect with the telephone network. You will have to buy a new phone.
This information has been confirmed by both Motorola and Nokia.
For more information, please visit Motorola or Nokia web sites:http://www.mot.com , http://www.nokia.com

There are over 3 million mobile phone being infected by this virus in USA now. You can also check this news in CNN web site:http://www.cnn.com

Please forward this information to all your friends who have digital mobile phones.

This is a HOAX. This is currently technically impossible. Please do not forward this HOAX on, as it only acts to keep it alive.

I have also been given permission to include the following posting that was made to the alt.folklore.urban newsgroup by an engineer from a mobile phone company.

It is in fact technically impossible. Here, roughly, is what happens when a call comes in to your digital cell phone:

The system "pages" the phone: "Hey, you, I've got something to say." The phone sends back a "yes, I'm here" message, and the system does some internal magic and assigns a dedicated channel to the phone for further discussion.

That further discussion includes caller ID information, instructions to start ringing, and so on, eventually including (presumably) voice traffic.

What it does *not* include is any discussion of what to do with the phone's IMEI (not IMIE) and IMSI. These are, in essence, the phone's identity[1]; the system can't reassign them.[2]

Exactly how this stuff is implemented is up to the manufacturer, but the usual routine would be to put the IMSI and IMEI in non-volatile memory, and require a specific service process (including entry of a top s3kr1t [secret] service code) to change them. There is no reason and no mechanism to change them through over-the-air operations.

It's just conceivable that there could be specific phone models with a bug allowing this data to be corrupted during normal operation; however, if it were as simple as "every call from an Unavailable number wipes the IMSI", such a bug could never have made it out the door of anybody's shop---it would be a showstopper on the same level as "every time you launch the application it crashes your machine".

"Virus", also, would be a misnomer. Phones aren't Turing machines as a rule; they tend to be implemented as very limited state machines, with no capacity to download and execute code, which would pretty well wreck the notion of a virus.[3]

I can't decide whether this looks like a mistake or a genuine hoax. One would think that anyone who knew the term "IMSI" would also know that This Can't Happen; on the other hand, the fact that "IMEI" was corrupted to "IMIE" suggests that the story has been through the hands of someone outside the industry. It may be a question of someone committing a gross mis-summary of information they didn't understand. This, however...

...is obviously hoactial[4]; someone who wrote this piece with legitimate intentions would have provided links to pages that actually said something, or not included the URLs at all.

Cite: Me. I draw a paycheck, at the moment, for being a liaison between the people who are testing a digital cell phone and the people who wrote the code for it. I have dreams about the difference between IS-41 and GSM, can tell you what TIA stands for, and know what an orthogonal function is and what it has to do with telecom. Good enough for ya?

These acronyms have the status of words in the telecom industry. You can read off a phone number from an IMSI; an IMEI has complex semantics that I know, in a certain literal sense, but don't really understand.

[2] It *can* assign something called a TMSI (pron. "tim-zee", stands for Temporary Mobile Station Identifier), in case there's a need for a local, temporary ID for a phone. At least, the relevant over-the-air standards permit it to; some systems implement that feature and some don't.

[3] Of course, one could put together a phone that placed data calls,
downloaded data, rendered it into some executable format and ran it; but you'd know if you had one of those, because you wouldn't pay for all the extra design and implementation labor unless that was a feature you wanted.

And it's a *lot* of extra work; that stuff isn't remotely similar to the normal behavior of cell phones.

[4] Do I gotta gloss everything? It's the adjectival form of "hoax", as any fule no; compare the universally understood "quincunctial".
--
Nathan Tenny, Qualcomm, Inc., San Diego, CA